import java.util.Scanner;

public class Demo_03 {
    public static void main(String[] args) {
        Scanner x =new Scanner(System.in);
        System.out.println("请输入你的成绩：");
        int m=x.nextInt();
        switch (m){
            case 60:
                System.out.println("成绩及格");
                break;
            case 80:
                System.out.println("成绩优秀"+Math.sin(Math.PI/2));
                break;
        }


    }
}
